There are various forms of cranes which can be divided as follows into three types, for example. The first type is that of mobile cranes which travel independently on the road. The traveling gears of the mobile cranes are raised from the ground with a large support at the construction site so that a large support base is produced with tilt edges which lie far apart. The bearing pressure under these supports is distributed almost homogeneously.
A further crane type is the crawler-mounted crane which has to be moved as a separate transport product on the road. The crawler-mounted crane can, however, move independently on the construction site. An inhomogeneous distribution of the ground pressure is produced beneath the base plate of the crawler.
Finally, as the third crane type, there is the so-called pedestal crane. This is also moved as transport product on the road. This pedestal crane is stationary at the construction site. It also has to be set up each time at every deployment location at the construction site.
Each of the aforesaid three types has advantages and disadvantages.
A mobile crane which has a modular design is already known from DE 10 2008 047 737, A1. It includes a platform module, an equipping module and a drive module as well as a support module. The modules can each be assembled and dismantled again.
A crane is known from DE 20 2010 002 947, U1, which positions a single-axle all-terrain dolly beneath the boom for travelling. The single-axle all-terrain dolly takes up the head weight of the boom.
It is the object of the invention to provide a mixed form of the initially named different crane types in which the advantages are utilized and the existing disadvantages are avoided as much as possible.
This object is solved in accordance with the invention by a crane in accordance with this disclosure. A crane is provided having an undercarriage with a swivel connection and having a superstructure rotatably supported thereon via the swivel connection and comprising at least one boom system arranged at said superstructure and luffable about a luffing axis or a self-climbing tower slewing crane rotatably supported thereon via the swivel connection. In accordance with the invention, the undercarriage has a pot as a central component which, on the one hand, receives the swivel connection. Furthermore, however, the pivotable supports can also be pivotally connected to it. Side members are present at mutually oppositely disposed sides and at least one traveling gear can respectively be connected to them with at least one degree of freedom.
A number of advantages of the initially named crane types can be realized with this conceptually newly designed crane. The new undercarriage concept can thus be set up on the construction site as a stationary base of a very stable design. After a corresponding setup, the traveling gear can be separated. After the separation of the traveling gear, it can, for example, take over another task at the construction site, for example in the form of a heavy load transporter.
On the other hand, the pot can selectively be connected to different traveling gears via the corresponding side members and the connections provided thereat to move the crane. On the one hand, it could be a track traveling gear which is advantageous for the movement of the crane on the construction site. On other hand, however, a wheel traveling gear can also be used.
Particular advantages of the invention result from other aspects of this disclosure.
Both the support and the side members can advantageously be releasably connected to the pot. This is in particular indicated with very large cranes in which the individual parts also have to be transported separately from one another.
In the same manner, it is advantageous that the side members are releasably connected to the traveling gears. This allows the replacement of the traveling gears or the decoupling of the traveling gears during stationary crane operation.
In accordance with another advantageous embodiment of the invention, the pot can be divided into two, with each part of the pot being releasably connected to a traveling gear via side members.
After their connection, the two parts of the divided pot form the swivel connection together with a revolving deck frame.
The releasable connection between the side members and the traveling gears advantageously takes place in that transverse struts having sliding shoes, rolls and/or rollers are arranged at the side members and cooperate with complementary ring elements at the traveling gear side such that the traveling gears can rotate beneath the side members.
The ring elements can advantageously be arranged on the traveling gear via a controlled three-point support or four-point support, with these advantageously comprising three hydraulic cylinders via which the ring element can be held in a horizontal position largely independently of the position of the traveling gear. A safe moving of the crane can hereby also be made possible off-road. This is in particular important when the crane is moved over a comparatively bumpy travel path off-road with comparatively widely spaced apart traveling gears.
It is of particular advantage if the traveling gears are configured in the form of modular heavy load transport vehicles. They can be driven or they can be not driven, with in particular the not-driven heavy load transport vehicles also being able to be adjustable in their widths in a manner known per se. It is very particularly advantageous, especially for transport on the construction site, that crawler travel gears are used as traveling gears. The advantage of a crawler traveling gear here is that it exerts a much more uniform bearing pressure on the ground than a comparable wheel traveling gear would. The crawler traveling gear is also of particular advantage with respect to the problem of the maximum axial load distribution on the travel path. The axial load of the wheel traveling gear namely has to be considered with corresponding wheel traveling gears. This very easily exceeds the permitted axial load (of, for example, 12, metric tons), in particular on the transport of large cranes.
The boom can particularly advantageously be supported via a separate additional traveling gear during movement. In this respect, the traveling gear can be coupled via correspondingly movable connection elements.
It is of advantage with respect to a particularly stable support if the supports are configured as lattice constructions which in this respect are also advantageously substantially designed with the same height as the pot itself. The supports configured as lattice designs have a particularly high stiffness. If they are designed exactly as high as the pot, the maximum transport height is also utilized so that in especially stable supports can in particular also be provided for the use of large cranes.
In accordance with a further advantageous embodiment of the invention, a control is provided for the common control of the traveling gears. Different traveling gear strategies can hereby be realized. All traveling gears can thus be orientated toward a common steering center, for example. Alternatively, two traveling gears can also be set to a common steering center beneath the ring elements, while the further traveling gear is steered separately beneath the boom.
Further features, details and advantages of the invention will be explained in more detail with reference to an embodiment shown in the drawing.